Arya (Sienna Guillory), elf princess of Ellesméra, flees with a strange stone, pursued by Durza (Robert Carlyle), a dark sorcerer under king Galbatorix (John Malkovich). When Durza corners Arya, she uses magic to teleport the stone away.
Eragon (Ed Speleers), a farm boy living in the country of Alagaësia with his uncle Garrow (Alun Armstrong) and cousin Roran(Chris Egan), is hunting for deer when he witnesses the stone appearing. Hoping to trade it for food, Eragon brings the stone home but realises it is actually an egg when a blue dragon hatches from it. As he touches the dragon, a magical mark appears on his palm. Several people are shown reacting to this incident, including Arya, Brom (Jeremy Irons), and Galbatorix himself.
Eragon shelters and feeds the dragon, and he teaches her to fly as she gradually grows to full size. She speaks to him through their thoughts and calls herself Saphira (Rachel Weisz). When they are out, Durza’s monstrous minions, the Ra’zac, arrive at the village to look for the dragon and the rider, killing Eragon’s uncle in the process. Blaming Saphira for his uncle’s death, Eragon sends her away. Brom shows up, takes Eragon away from the village, warns him of Saphira’s importance, and urges him to call her back. Eragon calls Saphira with his thoughts, and she comes back, forgiving him for what he previously said.
Brom is leading the group to the Varden, rebel freedom fighters opposing Galbatorix. On the way, Brom fills Eragon in on the knowledge of dragon riders, Galbatorix, Durza, and the Ra’zac. He also trains Eragon in sword-fighting. In a small village, Eragon meets a fortune-teller named Angela (Joss Stone), who tells him of a girl awaiting his help and of his dangerous path ahead. When Brom and Eragon are attacked by Galbatorix’s servants, the Urgals, Eragon attempts to mimic Brom and wipes out the whole group with a magic attack of blue fire, before falling unconscious from the strain. Saphira saves him. Brom teaches Eragon to control his magic and bond his powers with Saphira. After flying for the first time, Eragon and Saphira help Brom kill the Ra’zac, and Brom reveals he was once a rider, his dragon killed by Morzan, a rogue rider allied with Galbatorix.
Durza sets a trap for Eragon, using Arya as bait. Hearing her telepathic calls, Eragon finds her, but is ambushed by Durza. Eragon is outmatched, and Brom arrives to help him, though he gets mortally wounded in the process. In a fit of rage, Eragon vengefully shoots an arrow into Durza’s head, causing him to disappear. The trio escapes, and Brom dies of his wounds while flying on Saphira. Eragon takes possession of Brom’s sword, Zar’roc, which previously belonged to Morzan.
Eragon confronts a hooded figure that has been following them. That figure reveals himself to be Murtagh (Garrett Hedlund), and guides them to the Varden. Once there, Murtagh is imprisoned by the Varden for being Morzan’s son. Soon after, Durza and his men surround the rebel camp. Eragon, Saphira, Arya, and the Varden prepare for battle and fight off Galbatorix’s forces. Murtagh frees himself during the battle and assists the Varden, saving the Dwarf King King Hrothgar (Gary Lewis) and proving his trustworthiness. Eragon and Saphira duel in the skies with Durza who rides his own beast. They eventually kill him, but Saphira is heavily injured. Eragon uses magic to heal her and once again passes out from the strain.
The following morning, Eragon awakes with Murtagh at his side. He fears Saphira may be dead but finds her fully healed. They catch up with Arya, who is on her way to Ellesméra to lead the elves in the coming war against Galbatorix. She calls Eragon “The great Shadeslayer”, and they part ways, promising they’ll meet again. Meanwhile, in his castle, a furious Galbatorix slashes at his hanging map of Alagaësia, revealing his immense pitch black dragon, Shruikan.
While the film was horrible in itself, the book series was great, They did it dirty but I did love Jeremy Irons in this film.